What kills more people than HIV, malaria and tuberculosis every year? Air pollution. Tack on fouled water and poisoning by toxic waste and pollution killed 8.4 million people in 2012—or nearly three times as many people as those three diseases. Combined.

The tools and technologies to cope with such pollution already exist and have been used for years to clean up the air and water in the richest countries, like the U.S. So maybe it's time to transfer that technology where it can save even more lives.